its a rockford fosgate 1 farad digital cap. I still get a little funny idle and my headlights and interior lights still dim if i have it playing loud, i only play it loud if i am moving so the car is a higher rpms. I am thinking of a second battery also, one in the trunk area. My car almost shut off on me once also playing music so loud my voltage dropped down to almost 10 volts (said the digital cap). but do some research thats what i did any people said to get a cap but it doesnt help when theres constant bass or just from playing it up loud
